赤霉素(GA)是一種在干細胞伸長、細胞分裂,、細胞分化,、種子發(fā)芽和開花等關鍵發(fā)育過程中起重要作用的植物激素,赤霉素生物合成抑制劑廣泛用于提高作物生長速度,。加快作物生長是纖維,、紙漿、木材和生物質(zhì)生產(chǎn)行業(yè)欲實現(xiàn)的一個重要目標,。以色列Tel Aviv大學的一組研究人員發(fā)現(xiàn),沉默煙草模式植物中的一種赤酶素失活酶能顯著改善作物的生長特性,。他們的這項研究發(fā)表于Plant Biotechnology Journal。
該組研究人員以赤酶素GA 2氧化酶為研究對象,這種物質(zhì)能在過表達GA 20氧化酶的情況下在植物體內(nèi)積累,GA 20氧化酶能催化赤霉素生物合成途徑的限速步驟,。與過表達GA 20氧化酶的品系相比,沉默GA 2氧化酶的品系生長速度更快,植株更高,因此使GA 2氧化酶沉默的方法更適用于木材和纖維行業(yè),。（生物谷Bioon.com）
生物谷推薦原始出處：
Plant Biotechnology Journal 13 Jan 2010 10.1111/j.1467-7652.2009.00480.x
Enhancing plant growth and fiber production by silencing GA 2-oxidase
Jonathan Dayan, Maayan Schwarzkopf 1 , Adi Avni and Roni Aloni*
Department of Plant Sciences, Tel Aviv University, Tel Aviv 69978, Israel
Enhancing plant height and growth rates is a principal objective of the fiber, pulp, wood and biomass product industries. Many biotechnological systems have been established to advance that task with emphasis on increasing the concentration of the plant hormone gibberellin, or on its signalling. In this respect, the most studied gibberellin biosynthesis enzyme is the GA 20-oxidase which catalyses the rate limiting step of the pathway. Overexpression of the gene resulted in an excessively high activity of the gibberellin deactivating enzyme, GA 2-oxidase. Consequently, this feedback regulation limits the intended outcome. We assume that silencing GA 2-oxidase transcription would abolish this antithetical effect, thereby allowing greater gibberellin accumulation. Here, we show that silencing the gibberellin deactivating enzyme in tobacco model plants results in a dramatic improvement of their growth characteristics, compared with the wild type and GA 20-oxidase over-expressing plants. Moreover, the number of xylem fiber cells in the silenced lines exceeded that of GA 20-oxidase over-expressing plants, potentially, making GA 2-oxidase silencing more profitable for the wood and fiber industries. Interestingly, crossing GA 20-oxidase over-expressing plants with GA 2-oxidase silenced plants did not yield consequential additive effects. Our findings unveil the benefits of silencing GA 2-oxidase to substantially increase tobacco growth and fiber production, which suggest using this approach in cultivated forest plantations and industrial herbaceous plants, worldwide.
